Most telescopes here on Earth are stationary, bound to a single location, often in a desert or on a mountain peak. But NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) isn't most telescopes.
SOFIA, for which NASA partnered with the German space agency (DLR), is a flying observatory. More specifically, it's a Boeing 747SP aircraft with a massive hole in its size, through which a 106-inch (2.7-meter) telescope takes in infrared views of the universe. SOFIA's 10-hour flights at 38,000 to 45,000 feet (about 11,500 to 13,700 meters) meant its instruments had to observe through much less of Earth's atmosphere, which blocks infrared light.
SOFIA began regular operations in 2014 and since then has been cruising through the night skies around the world, looking at the cosmos, but its last science campaign was scheduled to conclude Wednesday (Sept. 28). The campaign marks the end of the observatory's three-year mission extension. Soon, it will be decommissioned, per the recommendation of the most recent astrophysics decadal survey, a document in which scientists evaluate research priorities for the next 10 years.
"Equipped with exceptionally talented and diverse teams of scientists, engineers and aviation experts, SOFIA accomplished a wide variety of scientific achievements that will have a lasting impact on our understanding of many aspects of astrophysics, from galactic evolution, star formation and planetary science," SOFIA project scientist, Naseem Rangwala of NASA's Ames Research Center in California, which managed the science aspects of the mission, told Space.com. "The professionalism, creativity and resilience of the SOFIA team, scientists and engineers, was best demonstrated during the most difficult and challenging phase of the COVID-19 pandemic." During that period, the team safely managed two international deployments.
We're taking a look back at some of SOFIA's most memorable discoveries during its eight years of service.
Discovering water in sunlit areas on the moon
In 2020, scientists announced that they had detected trace amounts of water in sunlit areas of the moon's Clavius Crater using SOFIA data. "Previously there were indications from other missions of presence of water on the sunlit part of the moon, but SOFIA was able to confirm it unambiguously by detecting a spectral feature unique to water molecules," Rangwala said. SOFIA has continued to study the moon since and recently discovered water in the moon's Moretus Crater.
It's not a lot of water — by comparison, the Sahara desert here on Earth has 100 times more water than what SOFIA saw in the Clavius Crater. Still, the water's presence could have implications for future NASA moon missions, including the VIPER rover, due to launch in 2024 to sniff out water ice at the lunar south pole, and the Artemis program to return astronauts to the moon for the first time since 1972.
